This invention relates to methods and apparatus for stamping and punching at several stations, a vehicle roof panel to provide an opening which facilitates sunroof installation.
Although a sunroof in a vehicle offers considerable convenience for enjoying the outdoors compared to a convertible and also offers a luxury element to the vehicle, sunroofs are subjected to significant extremes in temperature, moisture and wind. Reliability of the sunroof can be affected. It is generally thought that factory installation of a sunroof offers the optimum fitment for the sunroof panel to ensure long time use and enjoyment.
Factory installation of the sunroof panel continues to be done by hand. The vehicle roof panel is manually manipulated for purposes of cutting out the opening for the sunroof, welding supporting structure to the underside of the panel about the sunroof opening and completion of the assembly. Usually the sunroof panel system is installed in the vehicle roof panel by two operators who manually position the assembly in the opening and secure it in place. Manual handling the roof panels can result in damaging the panels, particularly when the panels are of considerable size, such as on large luxury vehicle, sport utility vehicles and the like. That explains why only small roof panels were handled manually. With the exceptionally large sport utility vehicles, usually the sunroof installation is done after market because it is impossible for operators to properly handle panels in moving them from station to station without inducing bending and buckling in the panel contour. Furthermore, automated installation of the sunroof panel assembly in the opening of the vehicle panel is difficult to achieve because of the precision fit of the sunroof panel relative to the flanges formed in the vehicle roof panel opening.
Examples of sunroof panel assemblies are shown in U.S. Pat. No. 4,601,511. Reinforcement ribs 3 are provided in the roof panel, usually for a utility vehicle or van. The region close to the opening for the sunroof panel 2 is reinforced by the use of cross members 5 which stiffen the roof structure and prevent bucking of the roof panel. The cross member prevents bending stress, as applied to the roof panel from concentrating at the front ends of the reinforcement ribs. U.S. Pat. No. 5,100,197 describes a vehicle roof panel having a reinforcement member provided on each side of the opening. The reinforcement appears to be welded to the dependent flange of the roof panel. Components of the sunroof panel system are then secured to this welded reinforcement item. There continues to be a need for automating the manufacture of sunroof openings in large vehicle panels as well as facilitating the automation of the installation of the sunroof panel system in the opening. It has been difficult for prior art systems to address these problems because no one appears to have given thought to an integrated system which provides the opening in the vehicle panel, secures reinforcement thereto and provides a completed vehicle roof panel which is ready for securement to the balance of the frame of the vehicle and then automated installation of the sunroof panel system. Furthermore, manual handling of the panels, particularly the larger sport utility vehicle, van and pickup truck units have been avoided because of the potential of damaging the Class I surface of the panel.
In accordance with various aspects of the invention, a method of forming an opening in a vehicle roof panel is provided which minimizes or eliminates damaging of the Class I surface and as well, prepares the opening in a manner to facilitate automated installation of the sunroof panel system.
In accordance with an aspect of the invention, a vehicle roof panel has a recessed preform in a top portion of the panel. The preform is stamped in the panel at a location to define a perimeter for a sunroof opening. The preform being characterized by having a first bend which defines the opening perimeter comprising rounded corner portions interconnecting a front edge, a rear edge and two side edges, a downwardly extending flange which becomes a sidewall of a sunroof opening, the flange extending inwardly for a length at least equal to a depth of a seal portion of sunroof panel perimeter and a second bend extending opposite to the first bend for interconnecting said flange to a base plate portion of the recess. The flange provides a locator surface on its underside for subsequent stamping, punching and processing stations.
In accordance with another aspect of the invention, in a method for stamping and punching at several stations an opening in a vehicle roof panel for a sunroof installation, the initial operation of stamping a preform recess in a top section of the panel defines a perimeter for a sunroof opening. The initial operation comprises:
i) locating the roof panel in a stamping press beneath a press die, the panel being fixed relative to the die to align die perimeter with a predetermined position for the sunroof opening perimeter in the roof panel;
ii) stamping the preform recess in the roof panel to provide the perimeter for a sunroof opening, the preform being characterized by having a first bend which defines the opening perimeter comprising rounded corner portions interconnecting a front edge, a rear edge and two side edges, a downwardly extending flange which becomes a sidewall of the sunroof opening, the flange extending for a length at least equal to a depth of a seal portion of sunroof panel perimeter and a second bend extending opposite to the first bend for interconnecting the flange to a base plate portion of the recess; and
iii) at subsequent stations using an underside surface of the flange to locate the panel for further processing.
In accordance with another aspect of the invention, an apparatus for bending lip portions of depending flange portions defining a trapezoidal shaped opening for a sunroof in a vehicle roof panel, such lip portions extending along front, back and both sides of such opening, such flange portions being supported by back up flanges of an interior reinforcing ring. The apparatus bends such lip portions under such reinforcing ring flanges to provide a lead in to facilitate installation of a sunroof panel system. The apparatus comprises:
i) a back up block mounted on a first carriage;
ii) a stacked stripper block on top of a die block mounted on a second carriage, the stripper block being moveable relative to the die block where the stripper block is supported in a start position by a compressible high pressure yield device;
iii) a variable speed extendible and retractable drive fixed at a first end to the first carriage and fixed at second end to the second carriage;
iv) a controller for controlling direction of movement of the drive;
v) the controller actuating movement of the drive in a first direction to advance the backup block towards and contact such interior flange of such reinforcing ring and upon contact of the backup block, the stripper block advances towards and contacts such depending flange of such roof panel, the controller continuing movement of the drive to clamp such flanges between the backup block and the stripper block and compress the yield device to advance thereby the die onto such lip portion and bend such lip under such reinforcing ring flange and against the backup block;
vi) whereby the backup block and the stripper block float in locating and contacting such flanges of such reinforcement ring and such roof panel on the front, back and both sides of the sunroof opening.
In accordance with a further aspect of the invention, a process is provided for preparing a trapezoidal shaped sunroof opening in a vehicle roof panel to receive a sunroof panel system, the opening having depending flange portion with lip portions at the front, rear and both sides of the opening, the flange portion being supported by back up flanges of an interior reinforcing ring. The process of bending the lip portions under the flange portions of the reinforcing ring to provide a lead-in to facilitate installation of a sunroof panel system
i) clamping the flanges of the roof panel and the reinforcing ring between a backup block contacting the interior ring flange and a stripper block contacting the flange of the roof panel;
ii) advancing beneath the stripper block, a die block to bend the respective lip portion beneath the respective flange of the reinforcing ring to provide the lead in portion at the front, rear and sides of the opening.